Two-pole approximation for high speed interconnect design

In this paper an approach to find two approximate poles for high speed interconnect design is presented. The approach overcomes the instability problem associated with Pade approximation. These two poles are used for rapid evaluation of line parameter changes. Since transmission line system is a stiff system with some poles of small magnitude and some poles of large magnitude, in general, it is impossible to match the simulated waveform with the calculated waveform using a small number of poles. The objective here is to evaluate efficiently the effect of parameter changes in our optimization process. Numerical examples show that the proposed approach can meet our objective